Yes, both building and using computers could technically be considered phenotypes because they are behaviors. The internet and computer are both behavior products of an organism, so that qualifies too. See, this is why I dislike terms like 'natural selection' and 'phenotype', people can misuse it and it does nothing but bring about confusion. We can't get the best definitions or understand something when we can apply the same term wherever it fits best.
Tell me, the pencil laying in front of me is a phenotype, can you tell me if is charcoal or graphite? What is the brand and current length of it? The ultimate question we can ask here: what isn't a phenotype?
Edit 2: You know, that gasoline in your car can be considered a phenotype as well. Partly, because they are a product of an organism, dead bodies do qualify here. And also, it is a product of human behavior, through processing petroleum from its raw form. Where does it end? What answers can you find thinking so broadly?